SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e184e199d348979422116af6ad6eaa5c0f0f39eb957f93cd11134712aa3dc27' 
  AND token = 'bxRtFtzy02llFQynikW0yeja4L45JzcO8iI1hpQLkeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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