SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '745bae09f3221502c0927515f56aee1966231bb06a2db1ad9d066476427950c6' 
  AND token = 'Ej7MufO03/hIm+nt1iT9fLO/FrPhTJu5sInugfWgNL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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