SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b024556ab138c63f5e41bfeecc545177e1a3e6ebac3591803e9f144429771b6' 
  AND token = 'SCvO6GlgS3tLxtTnatIij8fv7KPIMW+0o7YdiLFIOFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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