SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb40f5a084e825ab3f4b19c937751156363e43654e372284b636b999d314eb2c' 
  AND token = 'ogLcB4qLx/60Q8Uh30EYHGfjxYW5JTaGpUZnEMn2+zM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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