SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6722820c5b967057d4222b1038967359792d5bb35d67f3887be8158e417581a3' 
  AND token = 'jkFt8BjLVtpp75rerA8cpKQryodWpRp+ReHGMlM70ls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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