SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be79fa67da21d347cff7e664f6ba29fd065f08d10f9259c8c2324cb0bac8c8bf' 
  AND token = 'Y5PLEqU8VXMNSnqHNhAoWtW/DxcpZY2wsY+GzOuDao0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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