SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75cedb3d7fc8ed3b46dd2fd621ae551b2ced56cce08dbb9fbda415f2d262435c' 
  AND token = 'DP7nslO+74LdLEJ/77/0W7BVko2b7W/+4z4+JxTesbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}