SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433bbaeb35bfa92520ba7d9add4c4f39e294813856729ac3a7d5228671a23726' 
  AND token = '4NDRHycK+1ztjJFDDKm4+Z6si52mPFfQDB1sLZBVCCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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