SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77942208646eb5b2428e4acff037ab0c64f21162f97e1ce2de91a82f84a36069' 
  AND token = 'bd/N4+/H01fss1KCXtXnusvJGZSv9ObxYFFOsUlYdm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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