SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e4468e698ee31a7c2acb44a7f525eb96b53fba39d8915811af1c4dc8880c964d' 
  AND token = '4VW8JqDmf6/L4tn2dH+WQnwzSb1dIdGvyhn4R5AK+YA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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