SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c426c2037fadedee7798da50f83db7b9822ecbb9ae6417120b40bd30678f3f02' 
  AND token = 'PmWpA9zOQhzUqsC4dIWwKEWDWc7BQlza5KuCmmkryVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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