SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e597333f7dd6652342f6aee659aa0b86e2da0e8a4c5f69b9e1b3b7d4fd41498' 
  AND token = 'Rqm8THhDveFKEnvSTlzVAZwWHitQfCG3Gc/KgrMitww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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