SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '401cf97ad5734ca6f4bfa338a27fdd33e079accfa18bb861c18655aa93d36feb' 
  AND token = 'MWT7xTOl3338o3zmfYgF76ltm+ZBRfTCoTiuXNIGkJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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