SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '576ab66b1174fa627364d23ec3a3d85b1fddd9bb6b775940a2e37602435c97c8' 
  AND token = 'XRpCplJ+mAVW5NlDRsKG9CGfUWCS/I9hyK1hL/WPE9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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