SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de47b8d6759b38db0c823c6df76d99d2e235168e96009f276dc4e1bbbca82862' 
  AND token = 'tG0E9BZOmhbdGGeJgNq7fmplryFtHK3cCRcvBHHHprk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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