SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a3315b88389de04aabe290a9c9ee802d261b01f2d1c6b020497f74adf35bb5c' 
  AND token = '0hSW/aFvCfRhJBvb+KKtOiaHUH4j8OCcijpmN0VYEyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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