SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d772f45eaf7d1e341e20b0f1ec2f23d5c2a513f91f15bcf3e90d8c584113ae9' 
  AND token = 'hS3YLaguPpCdrkxGwbS+iEAnzb/GNd5aidA+lHbY960=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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