SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1f9560d81e116891bb7fa5c21c68bd5f4c7812aa5be540626da6487aef9b2e' 
  AND token = 'PVYntPCFP/p0nQOGt2AXBO4/K2vz/Uj95OZwlBsyXTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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