SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '933ab1948023a78de3aac8ba255124fb411c17a500cbee4fa755b2a9a5e829eb' 
  AND token = 'AWn1phbpfbi7FaENjKhntwy8dDFXrJwabtFMQp8f2nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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