SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52291031087bcc62c6f70c5b2714d1d1fb18abcf717df181537324eee33d8041' 
  AND token = 'gC+euKVRM/jglwK1Ls1MoXbyGbvqWDp8RQLDzu9MDoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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