SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbbc66440cb25f6325d0f00ad202be8cb1d7f1e72c164fc0dbd5d14fc8c578a9' 
  AND token = 'v0D193+NkAOcFYpmCMGAzRzPKxasy+V2hl/MEjgLSBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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