SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3a1466cfd68bd83761ab06217b1fdbe9e07b74a9efd33d73a85c7fbb1f8267b' 
  AND token = 'VbnOuG6pt7EVaFxsOgoRLHCs4DCDnR+rWpENqH9G4Sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}