SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '543e2f3cc0dccbab58615dfaca05a1e4fe66bac89a947f7d1c18f95229f8f953' 
  AND token = 'KesO5/85mkO6x/gXYSKJ3hWj4EOWgx7cLcGCcZYrzJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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