SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39d48888134b8aae541dbb5c7899e4de9178cfa3231f89ed47b45971e7f9feab' 
  AND token = 'WGOjJPWCYtCJpOg+/8WMLBg9gwOrFyocu+oCRJVsznE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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