SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18954a0da38c5b39296128277123b2b940e4f74710fe2ff9c3eaf74412c657f8' 
  AND token = 'NyfXuYkFnfPSA9zpSpgmF+Y93Ze2FXCYMci6nvSnwWo=' 
  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"
    }
  }
}