SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c26ac36aabfedf22839520b3bf2e204091a1eff2c531e9d9c9cb709ca15189f' 
  AND token = 'XNbhoD0xQGf4nrZjJ6RH5iKYMfOy1XcfW07gAFOTmh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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