SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfba4322f079257d25345b15d45ea33af0367ef13e12611d721aabda11f65b9e' 
  AND token = 'k9Nm8jMHimCL68xSKwgKYDgA/0y93oMWAuUnHabhQgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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