SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c9c0ddc7b915d7e99e1b273d7bb1350a679f89da85899c006937a73afec0860' 
  AND token = 'WHqsoXTAl6ISuLnrg0Cpe3ql/IbdFrhvSysBxJlb/nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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