SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75e19e4b58994fa1657e8972c90c6e9db8050c9bfc4e50ebec6c39d04689cb90' 
  AND token = 'MuG5MMbJMM0kjrOOhoqQRGRuMIbPppq+UITco8L6PD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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