SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d3458ce272ae1345aab174d26e0654e251cd6e58e2758bd5fd1d5c5edf9bb79' 
  AND token = 'wbhoTMlMltI/sK3Dyn3jI9fno25AWoPehaDGshlKbVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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