SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e75cbb963f94fd215bb8ab2b0701c097cc82535c97626a659bdd9756836dcf3' 
  AND token = 'tHMkyY8H1yma1O+PWkPFl6UyAIZFIt04x27GFagXhgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}