SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a5a9af036890323d57398c52f52516332fedd5a69fc8516856937421a1759a1' 
  AND token = 'odOy3YIsT+sM7LPOII/URN8hKlPXw7lXCVPARbTARPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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