SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f243b066be6bd5156713f32c8114b2563bb173778833fce49def8e48942bee6' 
  AND token = 'XBXt/Fcj2/ulXHjysSIx0dZxmslQq2/3SdkgfErgCzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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