SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de70e03e69a0d864ceaf2f788524c66a2ebe38e7ddc1993e00529fcdc3f0964c' 
  AND token = 'HR25F0UuFr6q/WNQUMxZrlzxH0+5/Q9eTU3kscDgraA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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