SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99ed804c026ade988f7dfa0f437aebbaa126d90067e1b9e38edf19a502658df3' 
  AND token = '7xcHV2URjqWKhG5x78TjaSmgkIV1yRFz+B7d5ZD3JB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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