SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f2e08875930c0394890200aef9b1797d69ca26f2da6210353c473b4ab2e974a3' 
  AND token = 'C185yPROgrQyhaZBiV/Yv9e7sbguT8sqr+fOH/NZimA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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