SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04ea79703c268758d84bffcdcf231d97ad4a010b583b09e047ab0e13df9c7939' 
  AND token = 'Ml8v5sPWtctQLkDfXLnaiu8KX4RgN4lKTXnQdOtHZMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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