SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec378bd1f2068c0d7fa194f8f29a153a7679c5181cf4df03f4136bfdd93ec8cc' 
  AND token = 'HsDkFuUTEmyxSrwApwyO6gdsnuQuhxkmABXAr1WUEgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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