SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b0a36d4e46f2edb84ad6c94f959fae29137d24962f1916b8e259c21fe94551a' 
  AND token = 'LpfvUSsB+NfzjzwuH4yjVi7XKgo88hESXFAnziXEA0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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