SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6901fb4fca4a41a1dca64430b8c6617505814d437bfaf9b3b10b73335e5f288d' 
  AND token = 'BzME2OCfj+LlkStbqVdYNtBa7QKjTF++EAm29X77Xps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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