SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c82b22c95202fd531a6707ac4e7fca39f79095edf2d2e118b4859acb704f18d3' 
  AND token = 'CIYlsmu/kMg3ifY77DWokSfMUqcwquBSZ7JRzDVzHzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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