SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92f40960e6f5731752d1aac773279332aade08b21aecdbf9b655a889b2088166' 
  AND token = 'wG2lejdGUesOyuF8EKb+0Ciy5y86nLpbvL/MISSnpGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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