SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93365dcbd726b549d4c0663b55d835010c349f39426251c357ac999e812ba848' 
  AND token = 'tMdQj67A1+Jkm5/IvBVYwKvqApq54f7G0TU2RfIsCsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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