SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8575438adad5cff2b706a98c156a2d7fd513bd5032a50b2c403311a24274bbca' 
  AND token = '6wyy4QLYURnTPHV7v9Xx+Wr3HsZfq4AI7x40yFBFTjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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