SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fde5cab442f9a566d19fcd09186aa03d54a98142ca0742fa41a813f97da0c661' 
  AND token = 'QVCydZ/M2yZIP+2kXrh/0EObexq3bgOBzqwwZ2qMnCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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