SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1107039ac8505d3fe4b0c5920595495286a83d2668258e578475a791749a46d' 
  AND token = 'QuMfGvUP1IJownGt4Vc8nAhBSJSjwePvQfJaFYmAEGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00179

JSON explain

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