SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '02fdcf1da8b3e5287d092bc69da94824bfeb3ae695aa704dd5685681ea5b5c3b' 
  AND token = '2zy8otqfDReZzrlOovgcDGQFIVv+/wrGiLuCU896ldw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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