SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c99ade684765f5ad837f75d260a0b8529b3befb02d7af3743f76c60e3f1e5aab' 
  AND token = 'ZzZgiBUR2LheQSshiQ67OYsOw5J86n4z2r6wzQSCUuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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