SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df694fad0ec0cf69b28835fb6142a933b6083a05887209c8ee5f2246937e1c17' 
  AND token = 'd6yoDrxQsYxnsUyXocsjnEuPsRaTjSS2FLVXkS4ZqFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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