SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '865f8dec6a1c026167c2df5929f12463f0ab3fabb087f4db5caa975c37317f83' 
  AND token = 'Hcg85lZDoM2Rxk42BKaBPjKaS3ocH8RDN+8R7tkySQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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