SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f216f626d66198bf98744458b1c696139a5f64b7dd9baf8916f3bb2b6a363e3b' 
  AND token = 'eFphYNUu53FVDIyHn+xlT47V6CibvG5srKC/MRED8qY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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