SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fb575004233ebb174fd51f4251998d1e0fe37bcf840d755c32b3127ac096283' 
  AND token = 'ywI7Co1HrFNKIJvZPqTIyFAAQ/PRlh+rJSOGQf5U2Kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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