SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '402b3e062622e5fb3cd85158255e31745bffec871afed80299054cdf4c4d8689' 
  AND token = 'RcXoXOaZuaszKvSURsMGB0fyhh3ceGal+AxzAoACX/I=' 
  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"
    }
  }
}