SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '585dec5b68a567f237793f988b666bd3b3fef7481efde0ceba3a3dfbdb1960d3' 
  AND token = 'JA6astUtBq2ZKOiaFfwOy62qARYvtO9TCmZUOUBQ5L0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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