SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79b0c3d0c4e0630f615224735a0be71f387689035268143e082185be572850d9' 
  AND token = 'NH17BPiETCjfNFsWGA2XRyqDVhZC0HIZ+VySZd15G0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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