SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3be3f5c72f869102a0c9193ec46d6a261fe50f367818c33a738dbd48d009bef' 
  AND token = '2tx0ikEySev7B4fbTi4daY57wN/oaqh800IrOLKKras=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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