SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf85c65fe16aabe16f7c5e413b473f3c0575e3b3a768329fed755c7da0fdc216' 
  AND token = 'K2QFGOoajRHyV1YcePlwCBDCGPI406qIpkacpeMRl4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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