SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934fd81d4b2d13b9bb126fcc722f6b11cfbdbf4867c664f06b3b598dafa4f70b' 
  AND token = 'FJ4a1SdlLybAYqqvlRh8zXUrs+pEBNmNHqQUPKv3yP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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