SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17a0ac3a70953f58e8eab84c4fea005024c0c47896dadc5fa6d3233104e6b122' 
  AND token = '6uRXkC6KWincjzYSgnl8RG7jN4vg95TWG398hAUTO1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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