SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94c6464940a5ad0b2d7d81ff6ebce4a5a6b824d506f7cd0088e2a53ce7d99d03' 
  AND token = 'TY0KR/vHyucPMjf9TOL4gjLUhZhUH6RYjf9tGQGqaxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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