SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe86b579c39de4de927b7034aa4a8dab5472d642f595d36f1fc06636f4f3a7ed' 
  AND token = 'nUcgwxt9F1K3HjlXVlk2WJ/saH/GHP9LqJnkgj2rldQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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