SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1501f349a5f5b93e197bc175f6f2ed4448bf8eb2bbe844394a5f07e508d8afea' 
  AND token = 'CShBmG/0EyeeC2YwNYuLSuS4EJNDe+q9VbtMSrWv2z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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