SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '09ad42f8281553663012c39ea7763cfe69f519e14012d7f10c83f2b5c250e5ed' 
  AND token = 'DaKypSjk5K+bE2AQqtQz0ZEKF9UKwMG4f5MVhUMOqqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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