SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf7a74bba0c9dfe58b95f1420cc4947c0245993025456f0cb445f8af6f78ddc6' 
  AND token = 'EtCvMhbp17+wpKJRTGbFNlLZmIRKTHHG1itE+sltabc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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