SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb0484426d3c0396133c533cd2068765c655f90a7463c2eeca6c42323761922' 
  AND token = 'fQ8DnwQFi+gyQbDxEmX5REWSQBGw0xyvfcoVrk8x1jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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