SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78c8d38c74cfe7702f6c44bafa3aea5019bacdb512b419b30fed918a63d8a6d6' 
  AND token = 'faWKYdAamh+2t+341+YHzBGCeNnnn5sfzZq7CTrVvZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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