SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7959a39ec0f5da79db11a85324508aefe2cda16937007caaa35c9f41f72b6ad7' 
  AND token = 'lMZ/UV3r5LYbjGP4XztuevvihrCw20SlTd9uQV+IAXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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