SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e42e5fccaa2b33cb25bf97660305952d2f5dfc1930b47837feb1e7b307e23a87' 
  AND token = 'sjFePzEnkk4uMqIrOAbOuMdOZpa97ToAQBNU9kPSBVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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