SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66d7758ae9f022adfcf51f387f8030318cf728d563c513ee2f53b60647e9c9c9' 
  AND token = '6lqFKei99yWulZNcaEAcLvporu2ZZYfg3ukqldbDwkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}