SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f250e68b32092b65b4353222319355a5d67838c68d263657465aa4d49de9f2d' 
  AND token = '3DBHywYiJUD5bxGThI92Tm6sR/WniDxm4vLRPcHe0h8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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