SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c03b2a74dfb231cb0a5c9776460ff459abfd231719a9feb576f4ad2efde5a45d' 
  AND token = 'BhbJGQeOT/DF+vKKXCydkg/nxvalWRSU51Qe3eIhyeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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