SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93d34a1a0a679e618cdc6e95070a06b2106f662aac8ef6b7ff9437e049400570' 
  AND token = 'UrgSZH7qqHC59pCWziZBNE4cZeJE0qezl1n6NOSmqCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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