SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db72e6f00be001feafd2c2cfcd25aeed74e73626bc8b24ea7737ae883529be55' 
  AND token = 'YoH2eKtGvSFs0rKTE0wxVDoG204lPe1YFssxWVnNDpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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