SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6832dc8f004098a30bfee719b2e53c4d0d404802ea8454ebfc9861df3036ae79' 
  AND token = 'l6t1D/qdHgL7OvZ5JvwRAqGBaCj6r/hmof2lzHknXQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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