SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2866e008d506921c4b4a46c3098262c347ec5f97e0c2ded1195262784e84e604' 
  AND token = 'Kgn3DKIwHc7w1dsMfzcFo2pJwzn8jyH5f0Czu3Wpp/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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