SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93cf8bc7406b575e5ccc667c0128200c68fcf7f7492a38fc0ddc1ff2ef155265' 
  AND token = 't/ZMxZtNy5eYKhrLrs2rivghdpbdgQVPeED8TtzHlkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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