SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6204fc57291f462b3d55f41363529adff30eef4b7f18df680c58c177fc8731b5' 
  AND token = 'cN76ShSUqBrY8AcoMHHm06cGqPkzvxewQSAuPt4sUTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}