SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a262827bc5afd8d2033ff7509a8cd0d23065d2ecd138844e3727dfb45e4e3c' 
  AND token = 'Tg0BhNl3Q8TN2dhroxfpix9xsLLybpNuZNSqxjfeNf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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