SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a8de95bbb084b78878a928130e23083aef8af51fc4cf55184d9cdca72542614' 
  AND token = 'M7+VXx3NP0OxggL0/UiLRmcP/Qpq+w0G80KA+vQHHX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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