SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d7a3059dd28943f204454d076fa44a8bc39dc28fc78009399630acd4006a65c' 
  AND token = 'eTRAIn6lUYJ4BNkO/SiFuPX1NAbjVtA/bAOSiZVbHqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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