SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2acd158aa59c09edbbc20d0e035540f22d7ac27d87ddeea28fff8eac7abf77f6' 
  AND token = 'D6mqE2l+qyEAIIwGG4tcL73PnLOWas9gcT2Qu2EfeTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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