SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c4046a2534eaa0acd01f23fe2f7de27abf71c09c7f43e5804d6901235f47848' 
  AND token = 'Pl5a0ijUSi3uc38LMutn67a1u36PXikstxD0MmUzC/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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