SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eb20e732147e14ca067ce3f6643009ac46745d788a471f90f59ad2667dcce422' 
  AND token = 'PbIGBOdtWRYHylFzDAHppZofOJlGE1wIuUqWfMgrB74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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