SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db5ce4be105a6b18418f51e11b61ec8445d85ba144e4803cb0461603a440d8e4' 
  AND token = 'jknS44TpoHHkcOfKcKwSqvlcP4z7zoAObxXWbKyLL3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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