SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbd6bb58cf4051805ef70de4386cf4a2b7cf49b67328fdbf99d53334d5828057' 
  AND token = 'gbHwTqCN1qsBXZ1U+Bv6++xjrF84sYOL2x3IeoyLYC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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