SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fa1de90e105fef740340b22069ae5a86d9d1b32c6abb7ec26e422ccef4b76f5' 
  AND token = 'yEUbWzavvw7hwcG11wePRe0QRLGi+/FNLO3z0rjC1vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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