SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f382dbc92181f53e7dbefaf89bdff9eb90bd0d8b16e4d00ed94e83be77ecb44a' 
  AND token = 'VPWcxqlrKmuFtoar+GUraZ38qjfZkamD6q2qdSVJsV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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