SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ac8694648696bacd83d4a4dd49ac02b6f4c820cd4830dfbe2c66630bc4f8cc8' 
  AND token = '8pH0hlLSZdVUtaUhJhrtKR9asnZAvxPCHHe3SnZ6/Yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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