SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd82afd79016efee9c1371faa2c804a8d130c854b7cbd9b8d2278e56c2373b5d2' 
  AND token = 'o+eOAdmgvkvJYfkqi4IA9/P1NoFRLLCsIp8ZBzOsjy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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