SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f99790a1c864c655ec48d7ccc900039bc44ceb5bf4758becadeb85a272b9b924' 
  AND token = 'fkMqJENvADrazlwwnBTLo4DiccEGcklnxENGB4LwVig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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