SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08e8214bcf841db84b957aab1acc86b578acaff859f82e1fc014bea5f2c42d7c' 
  AND token = 'R9cnryEdhKarn4y5w0slHqtDC5jUKS2dEsoopAfFtcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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