SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '430c2b2acc1ceba02af250372bda34aebfffdff2e092fe4ecc82b2c7f04426da' 
  AND token = 'tom1bVDqO63i1q24DW6DttQhzKx2AaawMFLuQf3mqrY=' 
  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"
    }
  }
}