SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3bfe41c892112799831e9b771e4e808bbab06af426719b55dc381e308d0ae7a' 
  AND token = '9czbOeWfK595qShLAbitmTdXn3kSLxSH/RKmXuCAyCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}